US3740937A - End down detecting means for automatic yarn piecing apparatus - Google Patents

End down detecting means for automatic yarn piecing apparatus Download PDF

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US3740937A
US3740937A US00192210A US3740937DA US3740937A US 3740937 A US3740937 A US 3740937A US 00192210 A US00192210 A US 00192210A US 3740937D A US3740937D A US 3740937DA US 3740937 A US3740937 A US 3740937A
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signal
yarn
carriage
producing
unit
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W Drake
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Maremont Corp
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Maremont Corp
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    • D—TEXTILES; PAPER
    • D01—NATURAL OR MAN-MADE THREADS OR FIBRES; SPINNING
    • D01H—SPINNING OR TWISTING
    • D01H15/00—Piecing arrangements ; Automatic end-finding, e.g. by suction and reverse package rotation; Devices for temporarily storing yarn during piecing
    • D01H15/013—Carriages travelling along the machines

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  • Heard 5 7 ABSTRACT First and second photoelectric units mounted uponthe carriage of an automatic yarn piecing apparatus movable along a textile spinning frame respectively detect whether the carriage is adjacent a yarn delivery zone of the spinning frame and whether yarn is present within each such zone. Variations from a preestablished norm in the photoelectric outputs of the units are converted into signals directed to a correlating circuit which includes a bistable memory device. The correlating circuit is effective to actuate a nand-gate type of control device that initiates a cycle of operation of the piecing apparatus when the carriage is in operative adjacent relationship to a yarn delivery zone wherein no yarn is detected.
  • the correlating circuit may be temporarily disabled when desired, by inhibiting its memory device and as when the carriage of the piecing apparatus moves past an end of a spinning frame, to negate the possibility of a piecing operation being then inadvertently initiated.
  • Inexpensive, durable and compact electrical components and circuits are employed to conserve space, to minimize manufacturing cost and maintenance, and to insure consistently reliable operation under adverse operating conditions.
  • the successful use of a conventional phototransistor and light source in the photoelectric yam-detection unit is achieved by restrictively limiting the vision of the phototransistor to a particular area of the spinning frame and by subjecting its electrical output to high-gain amplification, preferably in the approximate order of 50,000 times, prior to signal-conversion thereof.
  • Such apparatus customarily includes a mobile carriage which moves along at least one spinning frame having a plurality of yarn delivery zones spaced longitudinally thereof. At each delivery zone which is inoperative due to the existence of an end-down or brokenyarn condition, the carriage is halted and the yarn discontinuity is eliminated, in any one of several possible ways, by suitable piecing or yarn-joining instrumentalities mounted upon the carriage. Upon completion of each piecing operation, the carriage resumes its movement and moves on to the next yarn delivery zone requiring end-down servicing.
  • the present invention is directed to an improved end-down detecting means, of the type employing photoelectric components, for an automatic yarn piecing apparatus.
  • the operation of the end-down detector for such an apparatus should rely as little as possible upon the use of mechanical-type switches, switch actuators, relays and like components which tend to fail after a period of use due to wear or, in some instances, due to exposure to the oft-times humid and lint-congested atmosphere prevalent within many textile spinning mills.
  • the use of vacuum tubes and other expensive, delicate and or bulky components should also be avoided.
  • the patroling carriage of a mere monitoring device may move continuously at a uniform velocity along each spinning frame which it services.
  • the location of the carriage in relation to each yarn delivery zone of the spinning frame or frames may therefore be ascertained, with a degree of accuracy sufficient at least for a monitoring device, by a timing process.
  • the carriage of a piecing apparatus must necessarily decelerate and stop, and thereafter accelerate and start, at each randomly-located yarn delivery zone requiring end-down servicing.
  • An end-down detector which determines carriage location by a timing process and by reliance upon a constant rate of carriage movement therefore does not possess the degree of reliability necessary in a yarn piecing apparatus. Due to the previously-mentioned serious consequences which are capable of ensuing from malfunction of the end-down detector of an automatic yarn piecing apparatus, it is decidedly preferable for such a detector to be a condition-responsive, rather than time-responsive, in all aspects of its operation.
  • the primary object of the present invention is the provision, in an automatic yarn piecing apparatus, of an improved end-down detector which is highly reliable in operation both initially and after extensive use; which is of a durable construction not easily adversely affected by shocks, impacts or exposure to a humid and lint-congested atmosphere; which is economical from the viewpoint both of initial cost and subsequent maintainence; and which is of such a compact construction as to not in any way impede the mounting or operation of the various piecing instrumentalities of the apparatus.
  • a related and more specific object of the invention is the provision of such an end-down detector which employs solid-state and integrated-circuit electrical components, including a plurality of nand-gate coincidence units or devices, virtually exclusively, and which is free from a vacuum tubes, oscilators tuned amplifiers, mechanical switches and switch actuators, relays and similar components which would tend to detract from the desired reliability, durability, compactness, and/or economy of the detector.
  • Another related and more specific object is the provision, in an apparatus of the type described, of photoelectric yarn-detecting and signal-producing means comprised of a conventional light source, a standard photo-transistor device and other components of equally simple, durable, inexpensive and compact construction, which are so positioned and interconnected as to produce an operating reliability and efficiency equal or superior to that achieved with more expensive, delicate and/or bulky components such as photomultiplier tubes, modulated light sources, tuned amplifiers, and the like.
  • Still another object is the provision, in association with the electrical circuitry of an end-down detector for a yarn piecing apparatus, of means by which the detector can be readily disabled when desired, as for instance upon movement of the carriage of the apparatus past an end portion of a spinning frame, and thereafter can be restored with equal facility to normal operation.
  • the present invention provides, in association with the carriage of an automatic yarn piecing apparatus movable along a textile spinning frame or like machine having a plurality of yarn delivery zones spaced along its length, first and second photoelectric signal-producing means for independently detecting whether the carriage of the apparatus is in adjacent relationship to one of the yarn delivery zones of the spinning frame and whether yarn is present within a particular area of each of such zones; a nand-gate (i.e., not and) type of control device effective when actuated to initiate a piecing operation of the apparatus, and so actuable by the coincidental receipt of actuating-type input signals at each of two input terminals thereof; and signal-correlating circuit means interconnecting the aforesaid first and second signal-producing means and the control device for actuating the latter when no yarn is detected by the second photoelectric means within a yarn delivery zone detected by the first photoelectric means.
  • first and second photoelectric signal-producing means for independently detecting whether the carriage of the apparatus is in adjacent relationship to one of the yarn delivery zones of the spinning
  • the signalcorrelating circuit includes a bistable memory device effective only when in a first operating condition to produce an actuating-type signal at one of the input terminals of the control device.
  • Such'memory device which is comprised of suitably interconnected nandgate units, is caused to assume or maintain its aforesaid first condition upon the detection by the first photoelectric means of the yarn delivery zone, and assumes its second condition only if yarn is detected within such zone by the second photoelectric means.
  • the signalcorrelating means further includes a branch circuit interconnecting the other input terminal of the control device and the first photoelectric means, and effective to produce an actuating-type signal at the other input terminal of the control device upon cessation of detection of the yarn delivery zone by the first photoelectric means. If no yarn is present within the yarn delivery zone, the production of the aforesaid signal actuates the control device and thereby causes the initiation of a yarn piecing operation.
  • control device and all nand-gate units of the signal-correlating means are of'intergrated circuit construction, and no mechanical switches, relays or timers are utilized.
  • inhibiting means is also provided to temporarily inhibit the memory device of the signal-correlating circuit when desired, as for instance upon movement of the carriage of the apparatus past an end portion of a spinning frame.
  • the memory device is maintained in its second operating condition, irrespective of signals produced by the first photoelectric means, and
  • the inhibiting means is comprised primarily of nandgate components similar to those employed in the signal-correlating circuit, and may be placed into and out of effect with facility.
  • the first and second signal-producing photoelectric means each includes a standard light-producing unit, a light-receiving unit of the phototransistor type, a potentiometer for balancing the output of the phototransistor so as to compensate for ambient light conditions, and a differential amplifier for producing an electrical signal in response to variations in the balanced output of the phototransistor.
  • the first photoelectric means which detects whether the carriage is adjacent a yarn delivery zone of the spinning frame
  • the light-producing and light-receiving units may be and are mounted quite closely to the supporting track upon which the carriage of the apparatus moves along the spinning frame.
  • a plurality of light-reflective strips which correspond in number and spacing to the yarn delivery zones of the spinning frame, are provided upon such track.
  • the highly reliable operation of the first photoelectric means utilizing only the conventional and relatively inexpensive components described above, is realized in large part by mounting of the light-producing and receiving units thereof in quite close confronting relationship, preferably within approximately one-half inch, to the carriage-supporting track and the reflective strips provided thereon.
  • the second photoelectric means which detects whether yarn is present within each delivery zone of the spinning frame, reliability of operation cannot be achieved in the same manner but nevertheless is realized without the use of bulky, highly sophisticated or expensive components.
  • the light-producing and light-receiving units of the second photoelectric means are similar to those described above and are adjustably mounted upon the carriage of the piecing apparatus, in vertically spaced and angularly inclined relationship to each other, for precise focusing upon an area of the spinning frame closely beneath the front or yarn-delivery pair of its drafting rolls. At such location fluctuations in the path of travel of yarn issuing from the delivery rolls, which fluctuations are occasioned by the customary vertical movement of certain of the spinning-frame components, are of minimal scope and a dead" or empty space exists rearwardly of the yarn path and between the suction-duct and roller beam of the spinning frame.
  • the inherently narrow field of vision of the phototransistor component of the light-receiving unit is further restricted by the lense component of such unit, preferably so as to encompass an arc of only approximately four degrees. While the output of the phototransistor of the light-receiving is extremely small under the described conditions, such output provides a highly reliable indication of whether yarn is present within the field of vision of the phototransistor and is capable of being greatly amplified without the normally-attendant noise or interference problems which would otherwise frustrate such amplification.
  • the phototransistor output is subjected to exceedingly high-gain amplification, which is preferably in the approximate order of 50,000 times and is achieved by the use of a twostage Darlington-type amplifier.
  • the thus-amplified phototransistor output is utilized in the remainder of the circuit of the second signal-producing means in substantially the same manner as the output of the phototransistor of the first signal-producing means is employed in the previously-described circuitry thereof.
  • FIG. 1 is a rear elevational view of an automatic yarn piecing apparatus mounted upon a fragmentarilyshown textile spinning frame or like machine and equipped with end-down detecting means in accordance with the invention
  • FIG. 2 is an enlarged view, partially in elevation and partially in vertical section, taken substantially along line 2--2 of FIG. 1 and showing one set of light producing and receiving units of the end-down detecting means, together with immediately adjacent components of the piecing apparatus and the spinning frame;
  • FIG. 3 is an enlarged view, partially in elevation and partially in vertical section, taken substantially along line 3-3 of FIG. 1 and showing another set of light producing and receiving units of the end-down detect ing means, together with immediately adjacent components of the piecing apparatus and the spinning frame; and
  • FIG. 4 is a schematic showing of the electrical circuitry of the end-down detecting means.
  • the spinning machine fragmentarily shown in FIG. 1 is of a conventional type having a plurality of yarn delivery zones spaced along each of its opposite sides. At each delivery zone of machine 10 yarn as roving normally passes downwardly from creel 12 through sets of drafting rolls 14, a guide number 16, and a control ring 18 to twist-inserting collecting means in the form of a rotating spindle-bobbin assembly 20 encircled by a spinning ring 22. On the side of spinning machine 10 fragmentarily shown in FIG. 1, drafting rolls 14 are mounted upon a roller beam 24 and a conventional suction-duct 26 (also shown in FIG.
  • All spindles of the spindle-bobbin assemblies 20 are supported by a stationary spindle rail 28, while all spinning rings 22 are supported by a ring rail 30.
  • ring rail 30, control rings 18 and guide members 16 are moved vertically during operation of machine 10 to traverse the yarn longitudinally of spindle-bobbin assemblies 20 as it is collected thereby.
  • the same arrangement of components is present on the opposite side of machine 10 not shown in FIG. 1.
  • the yarn piecing apparatus 32 shown in FIG. 1 comprises a mobile carriage 34 mounted as by a track 36 and overhead rail 38 for patrolling movement, illustratively in the leftward direction indicated by the arrow in FIG. 1, longitudinally of and closely adjacent at least the illustrated one side of spinning machine 10, to any one of its yarn delivery zones requiring servicing by reason of an end-down condition thereat.
  • carriage 10 might of course be contructed so as to patrol in the opposite direction, or alternately in both directions, and normally would be so mounted as to be capable of movement along and servicing of more than a single side of one spinning machine 10.
  • a cycle operation of apparatus 32 Upon arrival of carriage 34 adjacent a yarn delivery zone of machine 10 at which an end-down condition is detected, a cycle operation of apparatus 32 is initiated. Upon initiation of each such cycle of operation, carriage 34 is halted in operative adjacent relationship to the yarn delivery zone requiring servicing, and suitable piecing instrumentalities mounted within the open center section 40 of carriage 34 repair the yarn discontinuity, after which movement of the carriage is resumed.
  • the mechanisms and instrumentalities employed for halting carriage 34 and for repairing the yarn discontinuity may be of various types and form no part per se of the present invention, which is directed to improved means for detecting end-down conditions at the various yarn delivery zones of spinning machine 10 and for initiating the aforesaid cycles of operation of apparatus 32.
  • such means generally comprises first photoelectric signal-producing means, which includes the respective light-producing and light-receiving units 42,44 best shown in FIG. 3, for detecting whether carriage 34 of piecing apparatus 32 is in adjacent relationship to a yarn delivery zone of spinning machine 10; second photoelectric signalproducing means, including the respective lightproducing and light-receiving units 46,48 best shown in FIG. 2, for detecting whether yarn is present within an area of each such delivery zone closely adjacent the front or delivery pair of rolls 14 of machine 10; a nandgate control device identified in FIG.
  • signal-correlating circuit means including a pair of nand units 52,54 (FIG. 4) so interconnected as to form a bistable memory device 56, interconnecting the aforesaid first and second signal-producing means and control device 50 for actuating device 50 when no yarn is detected by units 46,48 within a yarn delivery zone detected by units 42,44; and means including additional nand units 58,60 and 62 for, when suitably actuated, inhibiting memory device 56 and thereby rendering control device 50 temporarily incapable of instituting a cycle of operation of apparatus 32.
  • All of the various nand units are of integrated circuit construction, and illustratively are each of the type which produces a low output signal only upon the coincidental receipt of high input signals at both inputs thereof.
  • light-producing and receiving units 42, 44 are mounted by a suitable bracket 64, which extends outwardly from carriage 34 in the direction of its patrolling movement, closely adjacent carriage-supporting track 36, the distance between units 42,44 and track 36 preferably being no more than approximately one-half inch. Both units 42,44 are of an inexpensive and commercially-available construction,
  • Units 42, 44 including a generally cylindrical housing having a lense at one end thereof.
  • a light bulb (not shown) and a phototransistor 66 (schematically shown in FIG. 4) of standard types.
  • Units 42, 44 are mounted in non-parallel relationship to one another (FIG. 3), such that the light beam emitted from unit 42 is received by unit 44 if reflected from the adjacent surface of track 36.
  • a plurality of reflective areas are provided upon the aforesaid surface of track 36, as by affixing strips 68 (FIGS. 1 & 3) of reflective tape or foil thereto.
  • the number and spacing of strips 68 along track 36 corresponds, in a manner which will be made more apparent hereinafter, to the number and spacing of the yarn delivery zones of spinning machine 10.
  • Units 46 includes a conventional light source (not shown) within its housing, for producing unmodulated light of only medium intensity, while the housing of unit 48 encloses a conventional phototransistor 70 (schematically shown in FIG. 4).
  • the inherently rather-limited field of vision of phototransistor 70 is further restricted by lense 72 of unit 46 so as to encompass an arc of only approximately four degrees.
  • Brackets 74 respectively mount units 46, 48 in vertically-spaced and substantially coplanar relationship to each other at a location within section 40 of carriage 34 closely adjacent the inner wall 76 of the leading (in relation to the direction of carriage movement) side section of carriage 34.
  • Each bracket 74 includes a first section secured to wall 76 by a bolt 78, and a second section secured to the first section by a bolt 80 and encircling the housing of the corresponding unit 46 or 48.
  • unit 48 is positioned so that its path of vision extends angularly downwardly toward and substantially normal to the usual path of travel of yarn issuing from delivery rolls 14, and on the opposite or rearward side of such yarn-path extends in closely adjacent but downwardly-spaced relationship to the suction duct 26 underlying delivery rolls l4 and into the "dead space between duct 26 and roller beam 24.
  • Light-producing unit 46 directs its beam of light upwardly at an angle such as to cause any yarn present at the aforesaid location to reflect light to unit 48, and as to discourage the receipt by unit 48 of whatever light might be reflected from those components of spinning machine 10 disposed rearwardly of the yarn path of travel.
  • the yarn closely adjacent such rolls therefore provides a target which, although quite small, is sufficiently stable as to be capable of photoelectric detection without the use of modulated and/or high-intensity light.
  • the vision of unit 48 can be precisely aimed at the aforesaid relatively stable target, with minimum possibility of the unit receiving reflected light other than from yarn thereat, as from suctionduct 26 or other components of spinning machine 10.
  • the upward inclination of unit 46, and its location in vertically spaced and substantially co-planar relationship to unit 48, also contribute to the aforesaid result.
  • the overall effect of the foregoing is for the receipt or non-receipt of reflected light by unit 48 to accurately indicate, with an exceedingly high degree of reliability, whether yarn is or is not issuing from delivery rolls 14 at the particular location beneath their nip and along their length then viewed by unit 48.
  • the relative spacing of units 42,44 and 46,48 and of reflective strips 68 is such that, as carriage 34 moves into proximity with each yarn delivery zone of machine 10, light is reflected from a corresponding one of the strips 68 to unit 44 (FIG. 3).
  • Each strip 68 is sufficiently long that light continues to be reflected therefrom to unit 44 as the further movement of carriage 34 transports units 46,48 (FIG. 2) to and through that location within the yarn delivery zone at which unit 48 will receive reflected light from yarn issuing from delivery rolls 14, if any such yarn is present within the zone. Further movement of carriage 34 transports units 42,44 beyond the aforesaid strip 68, whereupon the light beam produced by unit 42 ceases to be reflected to unit 44.
  • units 42,44 and 46,48 are mounted forwardly, in relation to the direction of movement of carriage 34, of the piecing instrumentalities within open center section of the carriage. This permits carriage 34 to be decelerated and halted, without the necessity of reversing its movement and without subjecting any of its components to undue stress, with the aforesaid piecing instrumentalities located in desired operative relationship to the yarn delivery zone at which an end-down condition is detected in the manner described.
  • FIG. 4 schematically illustrates the electrical circuitry by which a piecing cycle of operation of apparatus 32 is initiated when no yarn is detected by unit 48 within a yarn delivery zone detected by unit 44.
  • Phototransistor 66 of unit 44 forms part of a first signal-producing subcircuit shown at the lower portion of FIG. 4 and further including current-limiting fixed resistors 82, clamping diodes 84, a potentiometer 86 and a differential amplifier 88.
  • Resistors 82 and diodes 86 protect other components of the circuit from damage by limiting the current and voltage at selected locations within the circuit to safe magnitudes. Potentiometer 86 permits balancing of the positive output voltage of phototransistor 66 against a fixed negative voltage.
  • Potentiometer 86 is adjusted such that when photo-transistor 66 sees only ambient light, differential amplifier 88 receives a low (negative or zero) input voltage and produces a high (positive) output signal; but when phototransistor 66 receives light reflected by a strip 68 from light-producing unit 42 (FIG. 3), and thereupon increases its output, differential amplifier 88 receives a high voltage input and produces a low (negative or zero) output signal.
  • the second signal-producing subcircuit which includes phototransistor 70 of unit 48 and is shown at the upper portion of FIG. 4, is similar to that described above in its inclusion of resistors 90, clamping diodes 92, a potentiometer 94, and a differential amplifier 96, all which of which perform the same basic functions as the corresponding components of the first signalproducing subcircuit.
  • the two subcircuits differ significantly in one important respect, however. Due to the relatively shielded location of units 42,44 and their extremely close proximity to reflective strips 68 (FIGS. 1 & 3), the output of phototransistor 66 is sufficiently great to reliably insure the described production of signals by amplifier 88.
  • the output of phototransistor 70 is, in comparison, much smaller than that of phototransistor 66, due to units 46,48 necessarily being mounted in a more exposed location and directed toward a smaller, more distant and less reflective target.
  • the second signalproducing circuit further includes a two-stage Darlington-type amplifier 98, which subjects the relatively weak output of phototransistor 70 to exceedingly highgain amplification, such amplification preferably being in the approximate order of 50,000 times. While it might be expected that such high-gain amplification would be frustrated by noise or background interference, such is not the case due, apparently, at least in significant part, to the vision of phototransistor 70 being restricted in scope and precisely focused as previously described herein.
  • the thus-amplified positivevoltage output of phototransistor 70 may be and is utilized in the second signal-producing subcircuit in the same manner as the unamplified output of phototransistor 66 is employed in the first subcircuit, that is, the amplified output of phototransistor 70 is balanced by potentiometer 94 against a fixed negative voltage, such that differential amplifier 96 produces a high output when phototransistor sees only ambient light, and produces a low (negative or zero) output when the light beam of unit 46 (FIG. 2) impinges upon yarn and is re flected thereby to phototransistor 70.
  • the output side of differential amplifier 96 is directly connected to one input of bistable memory device 56, specifically to input A of its nand unit 52, and the output nal A of control device 50.
  • the output side of differential amplifier 88 is connected to the second input of control device by a branch circuit including signal everters 102,104 and a capacitor 106 therebetween, and is additionally connected to the second input (terminal B of nand 54) of memory device 56 through signal everter 102, input terminal B of nand unit 62, and a capacitor 107.
  • memory device 56 is effective in a first one of its bistable operating conditions to produce an actuating-type input signal at control device 50, specifically at input A thereof, but is ineffective in the second of its operating conditions to produce an actuating-type signal at control device 50.
  • control device 50 is actuated and initiates a cycle of piecing operation of apparatus 32 only when both inputs of the device are high, at which time its output becomes low.
  • Memory device 56 therefore is effective in its first operating condition to produce a high input signal at terminal A of control device 50, and in its second operating condition to produce only a low signal.
  • Condition changes of memory device 56 of course occur only in response to signal variations at alternate ones of its two inputs (i.e., input A of nand 52 and input B of nand 54).
  • device 56 changed from its first to its second bistable condition in response to a signal variation at input A of its nand 52, a change back to its first bistable condition is producible only by a signal variation at input B of its nand 54. It therefore follows that by prohibiting variations in the signal at its aforesaid terminal B, memory device 56 can be inhibited and prevented from assuming its first operating condition.
  • nand 62 comprises part of means for inhibiting, as aforesaid and at desired times, memory device 56.
  • Such inhibiting means further includes (see the left-center portion of FIG. 4) a second memory device 112, which is similar to memory device 56 and is comprised of suitably interconnected nand-gates 58,60, and a pair or normally-open switch elements 114,116.
  • the output of memory device 112 is normally high, and is received by input A of nand 62.
  • Closure of switch 114 grounds one input (terminal B of nand of device 112, thereby changing its output to low and producing the desired inhibiting action in a manner described more fully hereinafter, and simultaneously grounds one input (terminal A of nand 52) of I memory device 52.
  • Closure of switch 116 grounds the of device 56 is directed to and received by input termiother input (terminal A of nand 58) of device 112 and resets the same by thereby causing its output to again become high.
  • Both inputs of nand 54 of memory device 56 are high, which causes its output and the input at terminal A of control device 50 to be low: that is, memory device 56 is in its second operating condition.
  • Input A of nand 52 is high, in accordance with the then high output of amplifier 96, while input B of nand 52 is low, in accordance with the output of nand 54.
  • the output of nand 52 of course has the same condition, that is high, as input A of nand 54.
  • the input to everter 104 is high, this being possible notwithstanding the then low output of everter 102 due to the capacitor 106 therebetween, which causes the output of everter 104 and input B of control device 50 to be low.
  • control device 50 Since both inputs of control device 50 are low, its output is high and ineffective to initiate a cycle of operation of apparatus 32. As noted previously, device 50 initiates a cycle of operation only upon a coincidental receipt of high input signals at both of its input terminals, at which time its output becomes low.
  • the final step in the sequence of operation occurs as continued movement of carriage 34 transports units 42,44 beyond the reflective strip 68 theretofore reflecting light from the former unit to the latter one.
  • the output of amplifier 88, and therefore the input of everter 102 change to high.
  • the output of everter 102, and therefore input B of nand 62 change to low.
  • the then-present combination of high and low inputs at nand 62 causes its output to become high. Since capacitor 107 does not discharge, however, no
  • control device 56 therefore remains in its second operating condition, and input A of control de vice 50 remains low.
  • the output of control device 50 thus remains high, even though input B thereof momentarily changes to high as the previously noted change in output of everter 102, from high to low, causes capacitor 106 to discharge and thereby produces a momentary low input and high output at everter 104.
  • FIG. 4 circuit Following recharging of capacitor 106, which transpires immediately and automatically after its aforesaid discharge, the entire FIG. 4 circuit is again in its original state and therefore is ready for passage-of carriage 34 into proximity with the next-adjacent yarn delivery zone of machine 10.
  • the locations of units 42,44 and 46,48 upon carriage 34 of apparatus 32 are such as to permit carriage 34 to be non-abruptly decelerated and halted, upon the detection as aforesaid of an end-down, with its centrally-mounted piecing instrumentalities in proper operative relationship to'the yarn delivery zone requiring servicing. Reverse movement of carriage 34 is not required.
  • FIG. 4 circuit Upon the completion by apparatus 32 of the piecing operation and the resumption of movement of its carriage 34, the overall state of the FIG. 4 circuit will be the same as that ordinarily possessed by it only immediately after phototransistor 66 sees a reflective strip 68. That is, memory device 56 will be in its first operating condition. This does change the previously described sequence of operation, however, except in the fact that memory device 56 merely maintains, rather than assumes, its first operating condition when phototransistor 66 sees the next reflective strip 68.
  • Termination of the period of inhibition of memory device 56 is effected, when desired and with equal facility, by momentary closure of reset switch 116. This grounds and produces a low input at terminal A of nand 58 of device 112, causing the output of device 112 and input A of nand 62 to change once again to high.
  • Switches 114,116 may of course be constructed for automatic actuation, at desired times and as by suitable photoelectric means (not shown) provided in association therewith, in a particular use-environment of apparatus 32.
  • an automatic yarn piecing apparatus adapted to service a textile spinning frame having a plurality of horizontally spaced yarn delivery zones whereat yarn normally passes downwardly from delivery rolls and past a suction duct to yarn collecting means, said apparatus including a carriage adapted to move along said spinning frame and to be halted upon institution of piecing operations adjacent yam-delivery zones requiring servicing by reason of an end-down condition thereat, improved means for detecting said end-down conditions and for initiating said piecing operations, comprising:
  • first photoelectric signal-producing means for detecting whether said carriage is adjacent a yarn delivery zone of said spinning frame
  • second photoelectric signal-producing means for detecting whether yarn is present within an area of each said zone closely adjacent said delivery rolls of said spinning frame
  • a nand-gate control device effective when actuated to produce an output signal initiating a piecing operation, said device having a pair of input terminals and being actuated by the coincidental receipt of actuating-type input signals at each of said terminals;
  • said signalcorrelating means includes a bistable memory device effective in a first operating condition to produce an actuating-type signal at one of said input terminals of said control device and ineffective in a second operating condition to produce an actuating-type signal at said one input terminal of said control device; said memory device assuming or maintaining said first condition thereof upon detection by said first means of a yarn delivery zone and assuming said second condition upon yarn-detection by said second means.
  • said signalcorrelating means further includes a branch circuit interconnecting the other of said input terminals of said control device and said means for producing an actuating-type signal at said other input terminal of said control device upon cessation of the detection of a yarn delivery zone by said first means.
  • said branch circuit includes capacitor means and signal-everting means for limiting the time of production of said actuating-type signal at said other input terminal of said control device.
  • Apparatus as in claim 2 and further including inhibiting means effective when actuated to inhibit said memory device and maintain the same in said second condition thereof irrespective of signals produced by said first signal-producing means.
  • said inhibiting means includes a nand-type unit within that portion of said signal-correlating circuit interconnecting said first signal-producing means and said memory device, said nand-type unit normally varying its output in response to signal variations of said first means and upon actuation of said inhibiting means being rendered unresponsive to signal-variations of said first means.
  • said inhibiting means further includes a bistable memory unit connected to the other of said input terminals of said nand-type unit, said nand-type unit varying its output in response to signal-variations of said first means when said memory unit is in a first operating condition and said nand-type unit being unresponsive to signal-variations of said first means when said memory unit is in a second operating condition, and switch means for varying as desired the operating condition of said memory unit.
  • said second signal-producing means includes a light-producing unit and a light-receiving unit mounted upon said carriage in vertically-spaced relationship to each other, the path of vision of said light-receiving unit extending through and substantially normal to the ordinary path of travel of yarn issuing from said delivery rolls of said spinning frame and projecting beyond said path of travel in closely adjacent but downwardly-spaced relationship to said suction duct of said spinning frame.
  • Apparatus as in claim 8 including means mounting said light-receiving unit and said light-producing unit upon said carriage for independent positional adjustment of each said unit about either of two axes.
  • said lightreceiving unit comprises a phototransistor device having a narrow field of vision, and lense means for further narrowing said field of vision of said phototransistor device.
  • said second signal-producing means further includes Darlingtontype amplifier means for subjecting the output of said phototransistor device to high-gain amplification.
  • said second signal-producing means further includes potentiometer means for balancing the output of said Darlington-type amplifier as required to compensate for ambient light conditions at said phototransistor device, and a signalproducing differential amplifier connected in series with said Darlington-type amplifier and responsive to uncompensated for variations in output thereof.
  • Apparatus as in claim 14, within said lightreceiving means includes a phototransistor, and said first signal-producing means includes potentiometer means balancing the output of said phototransistor to compensate for ambient light conditions thereat, and a differential amplifier connected in series with said phototransistor and responsive to uncompensated for variations in said output.
  • said reflecting means comprises a reflective strip for each of said delivery zones of said spinning machine, and said signalproducing means is responsive to movement of said units thereof both into and out of confronting relationship with each said reflective strip.

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  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Textile Engineering (AREA)
  • Spinning Or Twisting Of Yarns (AREA)
  • Filamentary Materials, Packages, And Safety Devices Therefor (AREA)
US00192210A 1971-10-26 1971-10-26 End down detecting means for automatic yarn piecing apparatus Expired - Lifetime US3740937A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US19221071A 1971-10-26 1971-10-26

Publications (1)

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US3740937A true US3740937A (en) 1973-06-26

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ID=22708705

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Application Number Title Priority Date Filing Date
US00192210A Expired - Lifetime US3740937A (en) 1971-10-26 1971-10-26 End down detecting means for automatic yarn piecing apparatus

Country Status (5)

Country Link
US (1) US3740937A (de)
CA (1) CA939218A (de)
CH (1) CH539143A (de)
DE (1) DE2163197A1 (de)
GB (1) GB1320654A (de)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4047371A (en) * 1975-12-13 1977-09-13 Hans Stahlecker Spinning machine facility with a plurality of open end spinning machines and at least one servicing instrument
US4263776A (en) * 1979-09-24 1981-04-28 Parks-Cramer Company Apparatus and method for interrupting textile yarn processing operations
US4763467A (en) * 1985-10-16 1988-08-16 Zinser Textilmaschinen Gmbh Method and means of controlling the stop of the feed of roving in a spinning machine
US20050017796A1 (en) * 2003-07-22 2005-01-27 Denso Corporation Input protection circuit

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE3942406A1 (de) * 1989-12-21 1991-06-27 Rieter Ag Maschf Bedienroboter zur bedienung einer spinnmaschine
JPH052624Y2 (de) * 1990-05-14 1993-01-22

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4047371A (en) * 1975-12-13 1977-09-13 Hans Stahlecker Spinning machine facility with a plurality of open end spinning machines and at least one servicing instrument
US4263776A (en) * 1979-09-24 1981-04-28 Parks-Cramer Company Apparatus and method for interrupting textile yarn processing operations
US4763467A (en) * 1985-10-16 1988-08-16 Zinser Textilmaschinen Gmbh Method and means of controlling the stop of the feed of roving in a spinning machine
US20050017796A1 (en) * 2003-07-22 2005-01-27 Denso Corporation Input protection circuit

Also Published As

Publication number Publication date
CH539143A (de) 1973-07-15
DE2163197A1 (de) 1973-06-14
CA939218A (en) 1974-01-01
GB1320654A (en) 1973-06-20

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